The HEI Engineering core provides highly technical engineering expertise to enable cutting edge technical solutions to practical problems faced by a diverse array of scientists. Engineering solutions are episodic in nature, requiring several months of highly skilled engineering expertise, but only infrequently. Individual investigators generally do not have sufficient engineering needs on a continuing basis to justify full-time engineering personnel. The Engineering Core will maintain expertise in rapidly changing technologies to support new and innovative enabling technologies for scientific applications. Modern auditory research involving auditory prostheses and hearing assessment systems depends heavily on real-time processing of digital information. The engineering core will maintain expertise in realtime digital signal processing (DSP) hardware and software (Aim 1). The engineering core will develop and maintain expertise on the communication interfaces such as USB and IEEE 1394 with host computers and specialized hardware/software platforms for laboratory instrumentation. (Aim 2). Many experimental applications require precise triggering and coordination of multiple pieces of equipment, on time scales as short as microseconds and for spatial resolution of image data in the micron range. The engineering core will develop and maintain hardware and software to allow precision control of diverse equipment. (Aim 3)